[asterisk-users] Pops & clicks at the end of sound files

[Steve Edwards]

Un-top-posting...

> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Neeraj 
> Chand Sent: Monday, June 06, 2011 7:12 PM

> We recently decided to get a professionally recorded set of prompts for 
> our asterisk based IVRs and received these as the following:

[snip]

> The problem I have is that at the end of every file there is a pop / 
> distortion after playback.

On Mon, 6 Jun 2011, Skyler wrote:

> I had a similar issue converting wav files one time. Ended up using sox 
> to convert to .sln as that ended up being the sounding conversion.
>
> I used the below command on a directory of files to convert:
>
> for a in *.wav; do sox "$a" -t raw -r 8000 -s -w -c 1 `echo $a|sed 
> "s/.wav/.sln/"` resample -ql; done

You can save a couple of 'process creations' by replacing '`echo $a|sed 
"s/.wav/.sln/"`' with '${a/.wav/.sln}'

I use sox to transcode my files. I've had occasional issues with pops
at the end of files. I suspected it was because of the DC offset my
voice talent introduces when they use their portable gear instead of their
studio gear.

I use Audacity to trim off the pop. It's manual, but it's faster than 
reordering the prompts.

FWIW, I use the following commands to convert to WAV:

 	sox "${INPUT}" -c 1 -s -w -r 8000 /tmp/$$.wav
 	normalize "${FILENAME}.wav"

Sox has a bunch of obtuse (IMNSHO) commands. There may be one that could 
automagically trim the pop for you.

-- 
Thanks in advance,
-------------------------------------------------------------------------
Steve Edwards       sedwards at sedwards.com      Voice: +1-760-468-3867 PST
Newline                                              Fax: +1-760-731-3000